Office chairs typically include an armrest supported thereon wherein the armrest has a support post on which the armrest is supported. Often, such armrests are adjustable in various directions to support the arm of the user and accommodate the unique physical characteristics of each chair occupant.
Such chair arms include adjustment mechanisms disposed between the support post and the armrest which allow for longitudinal movement in a front to back direction or lateral movement in a side to side direction which is transverse to the longitudinal direction. Also, such armrests have been made angularly adjustable and in some mechanisms, the angular adjustment is provided in combination with longitudinal and lateral adjustment.
It is an object of the invention to provide an improved chair arm arrangement which permits longitudinal, lateral and angular displacement of the armrest relative to the support post.
The invention relates to an improved armrest wherein the longitudinal, lateral and angular displacement of the armrest is governed by intersecting or overlapping slots on the armrest and support post wherein guide pins are slidably received through each pair of overlapping slots. More particularly, the support post includes a longitudinal slot and a transverse slot which are longitudinally spaced apart generally in the same plane, while the armrest includes a similar but oppositely oriented arrangement of a transverse slot and longitudinal slot. As such, the transverse slot on the armrest is disposed directly above the longitudinal slot on the support post with a guide pin being slidably received therebetween. Similarly, the longitudinal slot on the armrest is oriented vertically above and cooperates with the transverse slot on the support post with an additional guide pin being slidably received therebetween. The cooperating pairs of intersecting slots allow for longitudinal and lateral displacement of the armrest. Additionally, the opposite ends of the armrest are movable in opposite lateral directions to each other to adjust the angular orientation of the armrest relative to the support post.
Further, the armrest includes an improved locking arrangement which allows for ready locking and restraint of the armrest in any longitudinal, lateral or angular position and any combination thereof. In this regard, one of the armrests and support posts includes two different patterns of locking formations wherein one pattern of formations are uni-directional and another pattern of formations are bi-directional. First and second locking pins are provided on the other of the armrest and support post with the first locking pin being engageable with the uni-directional formations so as to be restrained only in a lateral or transverse direction and the second locking pin being engageable with the bi-directional formations so as to be restrained in both the longitudinal and transverse directions.
While the locking pins are spaced a fixed distance away from each other along the longitudinal axis of the armrest on which they are mounted, the relative distance along the longitudinal axis on the armrest support post varies depending upon the angular orientation of the armrest relative to the post. As such, engagement of the first locking pin with the bi-directional formation, which preferably is a circular opening, restrains one end of the armrest both laterally and longitudinally and defines the longitudinal position of the armrest relative to the support post. The engagement of the second locking pin with the uni-directional formation, which formation preferably is a slot, restrains the armrest transversely and defines the transverse position of the opposite end of the armrest. While the longitudinal position of the second locking pin varies depending upon the angular orientation of the armrest, the second locking pin is not confined in the longitudinal direction of the slot such that the slots accommodate the various angular positions in which the armrest may be oriented while greatly facilitating alignment of the pin with the slots and avoiding misalignment problems.
The armrest of the invention therefor provides for improved displacement of the armrest as well as improved locking thereof. Other objects and purposes of the invention, and variations thereof, will be apparent upon reading the following specification and inspecting the accompanying drawings.